Multi-input-multi-output (MIMO) communication is defined in the IEEE 802.11n standard. In MIMO communication, all the streams simultaneously transmitted from a plurality of antennas are transmitted to a wireless terminal. This is referred to as single MIMO communication. Meanwhile, a stream is transmitted from an antenna.
The IEEE 802.11ac standard is now being formulated as a next generation communication standard of the IEEE 802.11n standard, and by this, communication by a multi-user MIMO method, which performs wireless communication between the wireless base station and a plurality of wireless terminals, is studied.
Unlike single-user MIMO communication, in multi-user MIMO communication, a plurality of streams simultaneously transmitted from a plurality of antennas may be transmitted to different terminals. In general, in the wireless communication including single-/multi-user MIMO communication, an uplink and downlink pair is often formed between the wireless base station and the wireless terminals and made the transmission and reception of the data.
In a wireless communication system in which a wireless communication device complying with multi-user MIMO communication and a wireless communication device which performs wireless communication according to a standard other than this standard are accommodated, it is required to efficiently transmit and receive the data.